Every fall I see green moss and black streaks on the shady

Hi. Bubbling paint on a shady wall is often a sign of moisture getting into the wood, not just cosmetic. We had GotRot check ours during Seattle Siding Repair work in Ravenna. The bubbling boards had soft spots underneath, so they replaced them and made sure the wall could dry out better. They also recommended trimming back the shrubs that kept that wall permanently damp. Honestly, clearing plants away from the house helped as much as the repair. Two winters later, the paint is holding.